They may look like your normal house dog, but these military dogs are highly trained, invaluable assets in the war on terror. They are capable of detecting explosives, finding enemies and chasing down anyone who tries to escape.

"The capability they [the dogs] bring to the fight cannot be replicated by man or machine," said Gen. David Petraeus, commander of U.S. forces in Afghanistan. "By all measures of performance, their yield outperforms any asset we have in our industry. Our Army would be remiss if we failed to invest more in this incredibly valuable resource."

The dogs are a fighting force on four legs that are able to parachute into action, rappel into combat and swim into a skirmish. They are outfitted with protective body armor and a powerful bite. According to the U.S. Air Force, the bite from a German shepherd, one of the breeds used by the military, has a force between 400 and 700 pounds.

Watch World News tonight at 6:30 PM ET to see these incredible dogs in action.

While its bite may be impressive, it is a military dog's exceptional ability to detect bombs that makes it indispensable to soldiers.

"They've spent millions of dollars trying to come up with the best bomb detection technology," said Rebecca Frankel, deputy managing editor of foreignpolicy.com, who writes "War Dog of the Week" for the site. "After all that money and all that time devoted to it, they've come to the conclusion that in fact a dog and a handler best any technology on the ground today."

The Taliban has also noticed the value of the dogs.

"It's unfortunate, but the Taliban has wisened to the fact that these dogs are so successful at uncovering IEDs and so they are actually a target," Frankel told ABC News. "If they have them [the dogs] out on a lead or let them go in front of the unit often times I do think they attract sniper fire earlier."

Last year, at a cost of more than $20,000 per unit, the SEALs bought four tactical vests for their dogs, according to The New York Times. The vests are reported to have infrared and night-vision cameras that allow handlers to use a monitor from up to 1,000 yards away to see what the dog sees. The handler is also able to communicate with the dog through a speaker on the vest.

Frankel says there are upwards of 3,000 dogs deployed and that using dogs in war is nothing new.

"Dogs have been fighting with U.S. soldiers for centuries ... unofficially in the Civil War and then officially inducted into the U.S. Army in 1942 for World War II."